Battery and method for manufacturing the battery

Abstract

The present invention relates to a battery and a method for manufacturing the battery. A battery is provided in which the reliability near the riveted portion of the terminal is appropriately improved. In a preferred embodiment of the battery (100) disclosed herein, a negative terminal (40) having a terminal lead-out hole (19) provided through a sealing plate (14) and a negative electrode collector (61) connected to the negative terminal (40) are provided. The negative electrode collector (61) has a through hole (61A) for the negative terminal (40) to be inserted, and the through hole (61A) has a tapered portion (61d) having an inclination that gradually increases the inner diameter along the insertion direction. Here, the negative terminal (40) is riveted at the tapered portion (61d) while being arranged in the through hole (61A), and an outer peripheral smooth portion (40a) having a step is formed on the outer peripheral edge of the riveted portion (40b), and there is a joint portion (61f) where the outer peripheral smooth portion (40a) is joined to the edge of the through hole (61A).

Description

Technical Field

[0001] The invention relates to a battery and a method for manufacturing the battery. Background Art

[0002] Batteries such as lithium-ion secondary batteries are lighter and have higher energy density than existing batteries. Therefore, in recent years, they are preferably used as power sources for vehicles such as electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), or as power sources for electronic products such as personal computers and mobile terminals.

[0003] This type of battery typically comprises: an electrode body having a positive electrode and a negative electrode (hereinafter also referred to as "electrode" for short); and a battery case for housing the electrode body. The battery case generally comprises: an outer casing having an opening for housing the electrode body; and a sealing plate for sealing the opening. In addition, a positive terminal and a negative terminal (hereinafter also referred to as "terminal") are mounted on the sealing plate, and the terminals are electrically connected to the corresponding electrodes via a current collecting member. Here, as an example of a method for connecting the terminal to the current collecting member, a method of inserting the terminal into a through hole provided by the current collecting member and welding the terminal after riveting the front end thereof can be cited (refer to Patent Documents 1 and 2 below).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-010743

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-125491 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In recent years, there has been a demand for the development of batteries with further improved reliability. The present inventors have conducted intensive research and have found that there is still room for improvement in improving the reliability of the rivet portion of the terminal.

[0010] The present invention has been made in view of the above circumstances, and its main object is to provide a battery having appropriately improved reliability near the rivet portion of the terminal. In addition, another object is to provide a method for manufacturing the battery.

[0011] Means for solving problems

[0012] According to the present invention, a battery is provided, which includes: an electrode body including a positive electrode and a negative electrode; a battery case including an outer casing having an opening for accommodating the electrode body and a sealing plate for sealing the opening; a terminal electrically connected to the positive electrode or the negative electrode and penetrating a terminal lead-out hole provided in the sealing plate; and a conductive member connected to the terminal. The conductive member includes a through hole for the terminal to be inserted, and the through hole includes a tapered portion having an inclination that gradually increases the inner diameter along the insertion direction. Here, the terminal is riveted at the tapered portion in a state arranged in the through hole, and an outer peripheral smooth portion having a step is formed on the outer peripheral edge of the riveted portion, and there is a joint portion where the outer peripheral smooth portion is joined to the edge of the through hole. In addition, the "conductive member" in this specification and claims includes a current collecting member (positive electrode current collecting portion, negative electrode current collecting portion) arranged in the battery case and an external conductive member (positive electrode external conductive member, negative electrode external conductive member) arranged outside the battery case. That is, the conductive member may be a current collecting member or an external conductive member.

[0013] As described above, by riveting the terminal at the tapered portion while the terminal is arranged in the through hole, a peripheral smooth portion having a step is formed at the outer peripheral edge of the riveted portion, so that the gap generated between the peripheral smooth portion and the edge of the through hole can be reduced. As a result, the peripheral smooth portion and the edge of the through hole can be joined with high precision, so that the reliability of the riveted portion of the terminal can be appropriately improved (the details will be described later).

[0014] In one aspect of the battery disclosed herein, the outer peripheral smooth portion has a substantially annular shape in a plan view.

[0015] In one embodiment of the battery disclosed herein, the through hole has a through hole first region at a position farther from the sealing plate than the tapered portion, and the through hole first region is formed to be substantially perpendicular to the surface of the conductive member surrounding the through hole. In addition, preferably, the through hole first region has a thickness of 0.2 mm or more in the insertion direction of the terminal.

[0016] In one aspect of the battery disclosed herein, the through hole includes a through hole second region at a position closer to the sealing plate than the tapered portion, and the through hole second region is formed substantially perpendicular to a surface of the conductive member surrounding the through hole.

[0017] In one aspect of the battery disclosed herein, a ratio of an outermost diameter of the caulked portion to an innermost diameter of the through hole is within a range of 1.05 to 1.15.

[0018] In one aspect of the battery disclosed herein, the outer peripheral smooth portion includes a region where the joining portion is not formed.

[0019] In one aspect of the battery disclosed herein, the outer peripheral smooth portion has a substantially annular shape in a plan view, and the joining portion has a non-annular shape in a plan view.

[0020] In one aspect of the battery disclosed herein, the conductive member has a recessed portion formed along an outer peripheral edge of the through hole.

[0021] In addition, from another aspect, a method for manufacturing any of the batteries disclosed herein is provided. The method for manufacturing the battery is a method for manufacturing a battery having the following components: an electrode body including a positive electrode and a negative electrode; a battery case including an outer casing having an opening for housing the electrode body and a sealing plate for sealing the opening; a terminal electrically connected to the positive electrode or the negative electrode and inserted through a terminal lead-out hole provided in the sealing plate; and a conductive member including a through hole for inserting the terminal. The manufacturing method of the battery includes the following steps: a preparation step of preparing the conductive member having a through hole, the through hole having a tapered portion, the tapered portion having an inclination that gradually increases the inner diameter along the insertion direction; an insertion step of inserting the terminal into the through hole; a riveting step of riveting the terminal at the tapered portion of the through hole to form a riveted portion on the terminal; an outer peripheral smooth portion forming step of forming a step at the outer peripheral edge of the riveted portion to form an outer peripheral smooth portion; and a joining step of joining the outer peripheral smooth portion to the edge of the through hole. According to the manufacturing method of the battery, a battery having appropriately improved reliability near the riveted portion of the terminal can be obtained.

[0022] In one aspect of the battery manufacturing method disclosed herein, in the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed so as to have a substantially annular shape in plan view.

[0023] In a preferred embodiment of the manufacturing method of the battery disclosed herein, the through hole has a through hole first region at a position farther from the sealing plate than the tapered portion, and the through hole first region is formed to be substantially perpendicular to the surface of the conductive member surrounding the through hole. By providing the through hole with the through hole first region, the gap generated between the peripheral smooth portion and the edge of the through hole can be more appropriately reduced. Thus, the peripheral smooth portion and the edge of the through hole can be joined with high precision, and therefore, a battery with more appropriately improved reliability near the riveting portion of the terminal can be obtained (details will be described later). In addition, preferably, the thickness of the through hole first region in the insertion direction of the terminal is 0.2 mm or more.

[0024] In a preferred embodiment of the manufacturing method of the battery disclosed herein, the through hole is provided with a through hole second region at a position closer to the sealing plate than the tapered portion, and the through hole second region is formed to be substantially perpendicular to the surface of the conductive member surrounding the through hole. By providing the through hole with the through hole second region, the through hole second region can bear the radial expansion of the terminal during riveting, and thus, deformation of the conductive member in the vertical direction (i.e., the insertion direction) can be appropriately prevented. As a result, a battery with more appropriately improved reliability can be obtained (details will be described later).

[0025] In one aspect of the battery manufacturing method disclosed herein, in the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed so that the ratio of the outermost diameter of the caulking portion to the innermost diameter of the through hole is in the range of 1.05 to 1.15.

[0026] In a preferred embodiment of the battery manufacturing method disclosed herein, in the joining step, a region where the joining portion is not formed is provided on the outer peripheral smooth portion. This is preferred because, for example, when laser welding is performed, it is easy to check the trajectory deviation of the laser.

[0027] In one aspect of the battery manufacturing method disclosed herein, in the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed to have a substantially annular shape in plan view, and in the joining step, the joining portion is formed to have a non-annular shape in plan view.

[0028] In a preferred embodiment of the manufacturing method of the battery disclosed herein, a recess is formed in the conductive member along the outer peripheral edge of the through hole. By forming the recess, the heat capacity near the bonding portion in the bonding process can be reduced (i.e., bonding can be performed with less heat capacity), thereby appropriately reducing the thermal impact on the surrounding resin member. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a perspective view schematically showing a battery according to one embodiment.

[0030] Figure 2 It is along Figure 1 A schematic longitudinal cross-sectional view taken along line II-II.

[0031] Figure 3 It is along Figure 1 A schematic longitudinal cross-sectional view of line III-III.

[0032] Figure 4 It is along Figure 1 Schematic cross-sectional view of line IV-IV.

[0033] Figure 5This is a perspective view schematically showing an electrode assembly mounted on a sealing plate according to one embodiment.

[0034] Figure 6 It is a perspective view schematically showing an electrode body to which a positive electrode second current collecting portion and a negative electrode second current collecting portion are attached according to one embodiment.

[0035] Figure 7 It is a schematic diagram showing the structure of a wound electrode body according to one embodiment.

[0036] Figure 8 It is schematically indicated Figure 2 A partial enlarged cross-sectional view of the vicinity of the negative terminal.

[0037] Fig.9A It is schematically indicated Figure 2 A partial top view of the vicinity of the negative terminal.

[0038] Fig. 9B It is schematically indicated Figure 2 A partial top view of the vicinity of the negative terminal.

[0039] Fig.10 It is a perspective view schematically showing a sealing plate to which a positive electrode terminal, a negative electrode terminal, a positive electrode first current collecting portion, a negative electrode first current collecting portion, a positive electrode insulating member, and a negative electrode insulating member are attached.

[0040] Fig.11 Yes Fig.10 A three-dimensional image of the sealing plate turned over.

[0041] Fig.12 This is a flowchart for explaining a method for manufacturing a battery according to one embodiment.

[0042] Fig.13 It is a partially enlarged cross-sectional view schematically showing the structure of a negative electrode first current collecting portion (specifically, a negative electrode first region) according to one embodiment.

[0043] Fig.14 The figures are used to explain a method for manufacturing a battery according to one embodiment. (a) is a figure showing a negative electrode terminal before riveting inserted into a through hole of a negative electrode first current collecting portion, (b) is a figure showing a negative electrode terminal being riveted, (c) is a figure showing a peripheral smooth portion formed at an outer edge of a riveted portion, and (d) is a figure showing a negative electrode terminal being joined (welded) to a negative electrode first current collecting portion.

[0044] Fig.15 This is a schematic cross-sectional view for explaining a battery insertion step according to one embodiment.

[0045] Fig.16It is a partially enlarged cross-sectional view schematically showing the vicinity of a positive electrode terminal according to another embodiment.

[0046] Fig.17A This is a partially enlarged cross-sectional view for explaining the structure of a negative electrode first current collecting portion (specifically, a negative electrode first region) according to another embodiment.

[0047] Fig. 17B This is a partially enlarged cross-sectional view for explaining the structure of a negative electrode first current collecting portion (specifically, a negative electrode first region) according to another embodiment.

[0048] Fig. 17C This is a partially enlarged cross-sectional view for explaining the structure of a negative electrode first current collecting portion (specifically, a negative electrode first region) according to another embodiment.

[0049] Fig.17D This is a partially enlarged cross-sectional view for explaining the structure of a negative electrode first current collecting portion (specifically, a negative electrode first region) according to another embodiment.

[0050] Description of Reference Numerals

[0051] 12 outer body

[0052] 14 Sealing plate

[0053] 20 Electrode assembly

[0054] 20a, 20b, 20c Electrode body

[0055] 23. Positive electrode tab group (electrode tab group)

[0056] 25. Negative electrode tab group (electrode tab group)

[0057] 30 Positive terminal (terminal)

[0058] 40 Negative terminal (terminal)

[0059] 50 Positive electrode current collecting part

[0060] 51 positive electrode first current collecting part (current collecting part)

[0061] 52 Positive electrode second current collecting part

[0062] 60 Negative electrode current collecting part

[0063] 61 Negative electrode first current collecting part

[0064] 62 Negative electrode second current collecting part

[0065] 70 Positive electrode insulating member (insulating member)

[0066] 80 Negative electrode insulating member (insulating member)

[0067] 100 Batteries. DETAILED DESCRIPTION

[0068] Hereinafter, several preferred embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. In addition, matters other than those specifically mentioned in this specification and necessary for the implementation of the present invention (for example, the general structure and manufacturing process of the battery that do not characterize the present invention) can be understood as design matters made by those skilled in the art based on the prior art in this field. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in this field. In addition, in this specification, the expression "A to B" indicating a numerical range means above A and below B. In addition, it includes the meanings of "greater than A" and "less than B".

[0069] In addition, in this specification, "battery" refers to a general storage device that can extract electric energy, and is a concept that includes primary batteries and secondary batteries. In addition, in this specification, "secondary battery" refers to a general storage device that can be repeatedly charged and discharged, and is a concept that includes so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, and capacitors (physical batteries) such as double-layer capacitors.

[0070] In addition, in the present specification and claims, "substantially annular" may include a case where the missing portion is approximately less than 30%, preferably less than 20%, more preferably less than 10%, and further preferably 0% (i.e., annular) when the length of the entire circumference is set to 100%. In addition, "non-annular" may include a case where the missing portion is outside the range described in the above "substantially annular" when the length of the entire circumference is set to 100%. Moreover, "the first region of the through hole (the second region of the through hole) is formed to be approximately perpendicular to the surface of the conductive component constituting the periphery of the through hole" is not limited to the case where the angle between the surface of the conductive component and the first region of the through hole (the second region of the through hole) is 90°, and may also include a case where the angle is close to 90° (for example, 90°±10°). In addition, it is more preferred when the above-mentioned angle is 90°.

[0071] <Battery 100>

[0072] Figure 1 It is a perspective view of the battery 100 . Figure 2 It is along Figure 1 A schematic longitudinal cross-sectional view taken along line II-II. Figure 3 It is along Figure 1 A schematic longitudinal cross-sectional view of line III-III. Figure 4 It is along Figure 1Schematic cross-sectional view of line IV-IV of FIG. In addition, in the following description, the reference numerals L, R, F, Rr, U, and D in the figure represent left, right, front, rear, top, and bottom, and the reference numerals X, Y, and Z in the figure represent the short side direction of the battery 100, the long side direction orthogonal to the short side direction, and the up and down direction, respectively. However, these directions are determined for the convenience of description and do not limit the arrangement of the battery 100.

[0073] like Figure 2 As shown, the battery 100 includes a battery case 10, an electrode body group 20, a positive terminal 30, a negative terminal 40, a positive electrode collector 50, a negative electrode collector 60, a positive electrode insulating member 70, and a negative electrode insulating member 80. Although not shown in the figure, the battery 100 also includes an electrolyte. The battery 100 is a lithium-ion secondary battery. The battery 100 is characterized by the structure near the rivet parts 30b and 40b of the terminals disclosed herein (in this embodiment, the positive terminal 30 and the negative terminal 40), and the structure other than this can be the same as before. The structure near the rivet parts 30b and 40b is an example of the structure near the rivet parts of the terminals disclosed herein.

[0074] The battery case 10 is a frame that contains the electrode assembly 20. The battery case 10 has a flat rectangular parallelepiped (square) shape with a bottom. The material of the battery case 10 can be the same as that used in the past, and there is no particular limitation. The battery case 10 is preferably made of metal, and more preferably is made of aluminum, aluminum alloy, iron, iron alloy, etc. Figure 2 As shown, the battery case 10 includes an exterior body 12 having an opening 12 h and a sealing plate (lid body) 14 that closes the opening 12 h.

[0075] like Figure 1 As shown, the outer body 12 has a bottom wall 12a, a pair of long side walls 12b extending from the bottom wall 12a and facing each other, and a pair of short side walls 12c extending from the bottom wall 12a and facing each other. The bottom wall 12a is roughly rectangular in shape. The bottom wall 12a faces the opening 12h. The area of ​​the short side wall 12c is smaller than the area of ​​the long side wall 12b. The sealing plate 14 is installed on the outer body 12 in a manner that blocks the opening 12h of the outer body 12. The sealing plate 14 faces the bottom wall 12a of the outer body 12. The sealing plate 14 is roughly rectangular in shape when viewed from above. The battery case 10 is integrated by joining the sealing plate 14 to the periphery of the opening 12h of the outer body 12 (for example, welding). The battery case 10 is hermetically sealed (sealed).

[0076] like Figure 2As shown, the sealing plate 14 is provided with a liquid injection hole 15, a gas discharge valve 17 and two terminal lead holes 18 and 19. The liquid injection hole 15 is used to inject the electrolyte after the sealing plate 14 is assembled to the outer body 12. The liquid injection hole 15 is sealed by a sealing member 16. The gas discharge valve 17 is configured to break when the pressure in the battery case 10 reaches a predetermined value or more and discharge the gas in the battery case 10 to the outside. The terminal lead holes 18 and 19 are respectively formed at both ends of the long side direction Y of the sealing plate 14. The terminal lead holes 18 and 19 penetrate the sealing plate 14 in the up and down direction Z. The terminal lead holes 18 and 19 each have an inner diameter of a size that can be inserted into the positive terminal 30 and the negative terminal 40 before being installed on the sealing plate 14 (before riveting).

[0077] The positive electrode terminal 30 and the negative electrode terminal 40 are respectively fixed to the sealing plate 14. The positive electrode terminal 30 is arranged on one side of the sealing plate 14 in the longitudinal direction Y ( Figure 1 , Figure 2 The negative terminal 40 is arranged on the other side of the sealing plate 14 in the longitudinal direction Y ( Figure 1 , Figure 2 on the right side of the Figure 1 As shown in FIG. 1 , the positive electrode terminal 30 and the negative electrode terminal 40 are exposed on the outer surface of the sealing plate 14. Figure 2 As shown, the positive terminal 30 and the negative terminal 40 are inserted through the terminal lead-out holes 18 and 19 and extend from the inside of the sealing plate 14 to the outside. The positive terminal 30 and the negative terminal 40 are riveted to the peripheral edge of the terminal lead-out holes 18 and 19 surrounding the sealing plate 14 by riveting. Figure 2 A rivet portion 30b, 40b is formed at the lower end portion.

[0078] like Figure 2 As shown, the positive terminal 30 is electrically connected to the positive electrode 22 of the electrode assembly 20 via the positive electrode collector 50 inside the outer casing 12. The negative terminal 40 is electrically connected to the negative electrode 24 of the electrode assembly 20 via the negative electrode collector 60 inside the outer casing 12. The positive terminal 30 is insulated from the sealing plate 14 by the positive electrode insulating member 70 and the gasket 90. The negative terminal 40 is insulated from the sealing plate 14 by the negative electrode insulating member 80 and the gasket 90. The positive terminal 30 and the negative terminal 40 are examples of the terminals disclosed herein.

[0079] The positive terminal 30 is preferably made of metal, for example, more preferably made of aluminum or an aluminum alloy. The negative terminal 40 is preferably made of metal, for example, more preferably made of copper or a copper alloy. The negative terminal 40 can also be formed by joining and integrating two conductive members. For example, the portion connected to the negative electrode collector 60 can also be made of copper or a copper alloy, and the portion of the surface exposed to the outside of the sealing plate 14 can be made of aluminum or an aluminum alloy.

[0080] like Figure 1 As shown, a plate-shaped positive electrode external conductive member 32 and a negative electrode external conductive member 42 are installed on the outer surface of the sealing plate 14. The positive electrode external conductive member 32 is electrically connected to the positive terminal 30. The negative electrode external conductive member 42 is electrically connected to the negative terminal 40. The positive electrode external conductive member 32 and the negative electrode external conductive member 42 are components to which busbars are attached when a plurality of batteries 100 are electrically connected to each other. The positive electrode external conductive member 32 and the negative electrode external conductive member 42 are preferably made of metal, for example, more preferably made of aluminum or an aluminum alloy. The positive electrode external conductive member 32 and the negative electrode external conductive member 42 are insulated from the sealing plate 14 by an external insulating member 92. However, the positive electrode external conductive member 32 and the negative electrode external conductive member 42 are not required and can be omitted in other embodiments.

[0081] Figure 5 1 is a perspective view schematically showing an electrode assembly 20 mounted on a sealing plate 14. The electrode assembly 20 here includes three electrode bodies 20a, 20b, and 20c. However, the number of electrode bodies arranged inside one outer casing 12 is not particularly limited, and may be two or more (plural) or one. The electrode assembly 20 here is supported by an electrode body holder 29 (see FIG. 1 ) made of a resin sheet. Figure 3 ) is configured inside the outer casing 12 in a covered state.

[0082] Figure 6 It is a perspective view schematically showing the electrode body 20 a. Figure 7 20a. In addition, the following detailed description is given by taking the electrode body 20a as an example, but the same structure can also be adopted for the electrode bodies 20b and 20c. Figure 7 As shown, the electrode body 20a includes a positive electrode 22 and a negative electrode 24. The electrode body 20a is a flat wound electrode body in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked with a strip-shaped separator 26 interposed therebetween and wound around a winding axis WL.

[0083] The electrode body 20a is arranged inside the outer casing 12 with the winding axis WL parallel to the long side direction Y. In other words, the electrode body 20a is arranged inside the outer casing 12 with the winding axis WL parallel to the bottom wall 12a and perpendicular to the short side wall 12c. The end surface of the electrode body 20a (in other words, the stacking surface where the positive electrode 22 and the negative electrode 24 are stacked) Figure 7 The end face in the long side direction Y) faces the short side wall 12c.

[0084] like Figure 3As shown, the electrode body 20a has a pair of curved portions 20r facing the bottom wall 12a of the outer body 12 and the sealing plate 14, and a flat portion 20f connecting the pair of curved portions 20r and facing the long side wall 12b of the outer body 12. However, the electrode body 20a may be a stacked electrode body in which a plurality of square-shaped (typically rectangular-shaped) positive electrodes and a plurality of square-shaped (typically rectangular-shaped) negative electrodes are stacked in an insulated state.

[0085] like Figure 7 As shown, the positive electrode 22 has a positive electrode collector 22c and a positive electrode active material layer 22a and a positive electrode protective layer 22p fixed on at least one surface of the positive electrode collector 22c. However, the positive electrode protective layer 22p is not necessary and can be omitted in other embodiments. The positive electrode collector 22c is in a strip shape. The positive electrode collector 22c is composed of a conductive metal such as aluminum, aluminum alloy, nickel, stainless steel, etc. The positive electrode collector 22c is a metal foil, specifically an aluminum foil.

[0086] At one end portion of the positive electrode current collector 22c in the longitudinal direction Y ( Figure 7 A plurality of positive electrode tabs 22t are provided at the left end of the longitudinal direction Y. The plurality of positive electrode tabs 22t are respectively oriented to one side ( Figure 7 The plurality of positive electrode tabs 22t protrude further than the spacer 26 in the longitudinal direction Y. The plurality of positive electrode tabs 22t are arranged at intervals (intermittently) along the longitudinal direction of the positive electrode 22. The plurality of positive electrode tabs 22t are each in a trapezoidal shape. The positive electrode tab 22t is a part of the positive electrode collector 22c and is made of metal foil (aluminum foil). The positive electrode tab 22t is a part of the positive electrode collector 22c where the positive electrode active material layer 22a and the positive electrode protective layer 22p are not formed (exposed portion of the collector). However, the positive electrode tab 22t may also be a component different from the positive electrode collector 22c. In addition, the positive electrode tab 22t may also be provided at the end portion on the other side of the longitudinal direction Y ( Figure 7 The right end portion thereof may also be respectively arranged at the two ends in the long side direction Y.

[0087] like Figure 4 As shown, the plurality of positive electrode tabs 22t are provided at one end portion in the longitudinal direction Y ( Figure 4 The plurality of positive electrode tabs 22t are stacked together to form a positive electrode tab group 23. The plurality of positive electrode tabs 22t are bent and curved in such a way that the ends on the outer sides are aligned. The positive electrode tab group 23 is electrically connected to the positive electrode terminal 30 via the positive electrode collector 50. The plurality of positive electrode tabs 22t are preferably bent and electrically connected to the positive electrode terminal 30. A positive electrode second collector 52 described later is attached to the positive electrode tab group 23. The dimensions of the plurality of positive electrode tabs 22t (the length in the long side direction Y and the width perpendicular to the long side direction Y, refer to Figure 7) can be appropriately adjusted in consideration of the state of connection with the positive electrode current collecting portion 50, for example, according to its formation position, etc. The plurality of positive electrode tabs 22t have different sizes from each other so that the outer ends are aligned when bent. The positive electrode tab group 23 is an example of the electrode tab group disclosed herein.

[0088] like Figure 7 As shown, the positive electrode active material layer 22a is arranged in a strip shape along the length direction of the strip-shaped positive electrode collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (for example, a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide) that can reversibly absorb and release charge carriers. When the entire solid content of the positive electrode active material layer 22a is set to 100% by mass, the positive electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The positive electrode active material layer 22a may also include any component other than the positive electrode active material, such as a conductive material, a binder, various additives, and the like. As a conductive material, for example, a carbon material such as acetylene black (AB) can be used. As a binder, for example, polyvinylidene fluoride (PVdF) and the like can be used.

[0089] like Figure 7 As shown, the positive electrode protection layer 22p is provided at the boundary between the positive electrode current collector 22c and the positive electrode active material layer 22a in the longitudinal direction Y. The positive electrode protection layer 22p is provided at one end portion of the positive electrode current collector 22c in the longitudinal direction Y ( Figure 7 The positive electrode protective layer 22p is provided at both ends in the long side direction Y. The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains an inorganic filler (for example, aluminum oxide). When the entire solid content of the positive electrode protective layer 22p is set to 100% by mass, the inorganic filler may account for approximately 50% by mass or more, typically 70% by mass or more, for example, 80% by mass or more. The positive electrode protective layer 22p may also contain any component other than the inorganic filler, such as a conductive material, a binder, various additives, and the like. The conductive material and the binder may also be the same as the material exemplified as the material that the positive electrode active material layer 22a may contain.

[0090] like Figure 7 As shown, the negative electrode 24 has a negative electrode collector 24c and a negative electrode active material layer 24a fixed on at least one surface of the negative electrode collector 24c. The negative electrode collector 24c is in a strip shape. The negative electrode collector 24c is made of a conductive metal such as copper, a copper alloy, nickel, stainless steel, etc. The negative electrode collector 24c is a metal foil, specifically a copper foil.

[0091] At one end portion of the negative electrode current collector 24c in the longitudinal direction Y ( Figure 7A plurality of negative electrode tabs 24t are provided at the right end portion of the longitudinal direction Y. The plurality of negative electrode tabs 24t are oriented toward one side ( Figure 7 The plurality of negative electrode tabs 24t protrude further than the spacer 26 in the longitudinal direction Y. The plurality of negative electrode tabs 24t are arranged at intervals (intermittently) along the longitudinal direction of the negative electrode 24. The plurality of negative electrode tabs 24t are each in a trapezoidal shape. The negative electrode tab 24t is a part of the negative electrode collector 24c and is made of metal foil (copper foil). The negative electrode tab 24t is a part of the negative electrode collector 24c (exposed portion of the collector) where the negative electrode active material layer 24a is not formed. However, the negative electrode tab 24t may be a component different from the negative electrode collector 24c. In addition, the negative electrode tab 24t may also be provided at the end portion on the other side of the longitudinal direction Y ( Figure 7 The left end portion thereof may also be respectively arranged at the two ends in the long side direction Y.

[0092] like Figure 4 As shown, the negative electrode tabs 24t are provided at one end portion in the longitudinal direction Y ( Figure 6 The plurality of negative electrode tabs 24t are stacked together to form a negative electrode tab group 25. The plurality of negative electrode tabs 24t are bent and curved in such a way that the ends on the outer sides are aligned. The negative electrode tab group 25 is electrically connected to the negative electrode terminal 40 via the negative electrode collector 60. The plurality of negative electrode tabs 24t are preferably bent and electrically connected to the negative electrode terminal 40. A negative electrode second collector 62 described later is attached to the negative electrode tab group 25. The dimensions of the plurality of negative electrode tabs 24t (the length in the long side direction Y and the width perpendicular to the long side direction Y, refer to Figure 7 ) can be appropriately adjusted in consideration of the state of connection with the negative electrode current collecting portion 60, for example, according to its formation position, etc. The multiple negative electrode tabs 24t have different sizes from each other so that the outer ends are aligned when bent. The negative electrode tab group 25 is an example of the electrode tab group disclosed herein.

[0093] The negative electrode active material layer 24a is arranged in a strip shape along the length direction of the strip-shaped negative electrode collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (for example, a carbon material such as graphite) that can reversibly absorb and release charge carriers. When the entire solid content of the negative electrode active material layer 24a is set to 100% by mass, the negative electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The negative electrode active material layer 24a may also contain any component other than the negative electrode active material, such as a binder, a dispersant, various additives, and the like. As a binder, for example, rubbers such as styrene-butadiene rubber (SBR) can be used. As a dispersant, for example, celluloses such as carboxymethyl cellulose (CMC) can be used.

[0094] The separator 26 is a member that insulates the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. As the separator 26, for example, a porous resin sheet composed of a polyolefin resin such as polyethylene (PE) or polypropylene (PP) is preferred. In addition, a heat resistance layer (Heat Resistance Layer: HRL) containing an inorganic filler may be provided on the surface of the separator 26. As the inorganic filler, for example, alumina, boehmite, aluminum hydroxide, titanium dioxide, etc. can be used.

[0095] The electrolyte can be the same as before, without any particular limitation. The electrolyte is, for example, a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes, for example, carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. The supporting salt is, for example, a fluorine-containing lithium salt such as LiPF6. However, the electrolyte can also be in a solid state (solid electrolyte) and integrated with the electrode assembly 20.

[0096] The positive electrode current collecting portion 50 forms a conduction path that electrically connects the positive electrode tab group 23 composed of a plurality of positive electrode tabs 22t and the positive electrode terminal 30. Figure 2 As shown, the positive electrode current collecting portion 50 includes a first positive electrode current collecting portion 51 and a second positive electrode current collecting portion 52. The first positive electrode current collecting portion 51 and the second positive electrode current collecting portion 52 may be made of the same metal as the positive electrode current collector 22c, for example, conductive metal such as aluminum, aluminum alloy, nickel, stainless steel, etc.

[0097] Fig.10 It is a perspective view schematically showing the sealing plate 14 . Fig.11 Yes Fig.10 A three-dimensional image of the sealing plate turned over. Fig.11 The sealing plate 14 is shown on the side (inner side) of the outer body 12. Fig.10 , Fig.11 As shown, the first positive electrode collector 51 is mounted on the inner surface of the sealing plate 14. The first positive electrode collector 51 is an example of the collector disclosed herein. The first positive electrode collector 51 has a first positive electrode region 51a and a second positive electrode region 51b. The first positive electrode collector 51 can be formed by bending a member by, for example, press working, or by integrating a plurality of members by welding and joining. The first positive electrode collector 51 is fixed to the sealing plate 14 by riveting.

[0098] The positive electrode first region 51a is a portion arranged between the sealing plate 14 and the electrode body group 20. The positive electrode first region 51a extends along the longitudinal direction Y. The positive electrode first region 51a extends horizontally along the inner surface of the sealing plate 14. A positive electrode insulating member 70 is arranged between the sealing plate 14 and the positive electrode first region 51a. The positive electrode first region 51a is insulated from the sealing plate 14 by the positive electrode insulating member 70. The positive electrode first region 51a is electrically connected to the positive terminal 30 by riveting (the details will be described later). In the positive electrode first region 51a, a through hole 51h is formed that penetrates in the up-down direction Z at a position corresponding to the terminal lead-out hole 18 of the sealing plate 14. The positive electrode second region 51b is a portion arranged between the short side wall 12c of the outer body 12 and the electrode body group 20. The positive electrode second region 51b extends from the end portion ( Figure 2 The positive electrode second region 51b extends along the up-down direction Z.

[0099] The positive electrode second current collecting portion 52 extends along the short side wall 12c of the outer casing 12. Figure 6 As shown, the second collector portion 52 of the positive electrode has a collector plate connection portion 52a, an inclined portion 52b and a tab joint portion 52c. The collector plate connection portion 52a is a portion electrically connected to the first collector portion 51 of the positive electrode. The collector plate connection portion 52a extends along the up-down direction Z. The collector plate connection portion 52a is configured to be substantially perpendicular to the winding axis WL of the electrode body 20a, 20b, 20c. A recess 52d having a thickness thinner than that of its surroundings is provided in the collector plate connection portion 52a. A through hole 52e penetrating in the short side direction X is provided in the recess 52d. The through hole 52e becomes a reference position for welding, and a joint portion with the first collector portion 51 of the positive electrode is formed around it. The joint portion is a welded joint portion formed by welding, for example, ultrasonic welding, resistance welding, laser welding, etc. A fuse portion may also be provided in the second collector portion 52 of the positive electrode.

[0100] The tab joint 52c is a portion attached to the positive tab group 23 and electrically connected to the plurality of positive tabs 22t. Figure 5 As shown, the tab joint portion 52c extends along the vertical direction Z. The tab joint portion 52c is arranged to be substantially perpendicular to the winding axis WL of the electrode bodies 20a, 20b, and 20c. The surface of the tab joint portion 52c connected to the plurality of positive electrode tabs 22t is arranged substantially parallel to the short side wall 12c of the outer body 12. Figure 4As shown, the tab joint 52c is formed with a joint J with the positive tab group 23. The joint J is, for example, a welded joint formed by welding a plurality of positive tabs 22t by ultrasonic welding, resistance welding, laser welding, etc. in a state where the plurality of positive tabs 22t are overlapped. The welded joint is arranged so that the plurality of positive tabs 22t are close to one side of the short side direction X of the electrode bodies 20a, 20b, 20c. As a result, the plurality of positive tabs 22t can be bent more appropriately, and a stable joint such as Figure 4 The positive electrode tab group 23 is shown in a bent shape.

[0101] The inclined portion 52b is a portion connecting the lower end of the collector plate connection portion 52a and the upper end of the tab joint portion 52c. The inclined portion 52b is inclined relative to the collector plate connection portion 52a and the tab joint portion 52c. The inclined portion 52b connects the collector plate connection portion 52a and the tab joint portion 52c in such a manner that the collector plate connection portion 52a is located closer to the center side than the tab joint portion 52c in the long side direction Y. In this way, it is possible to expand the storage space of the electrode body group 20 and achieve a high energy density of the battery 100. The lower end of the inclined portion 52b (in other words, the end on the bottom wall 12a side of the outer body 12) is preferably located below the lower end of the positive electrode tab group 23. In this way, a plurality of positive electrode tabs 22t can be bent more appropriately to stably form a positive electrode group 23. Figure 4 The positive electrode tab group 23 is shown in a bent shape.

[0102] The negative electrode current collecting portion 60 forms a conduction path that electrically connects the negative electrode tab group 25 formed of a plurality of negative electrode tabs 24t and the negative electrode terminal 40. Figure 2 As shown, the negative electrode collector 60 includes a negative electrode first collector 61 and a negative electrode second collector 62. The negative electrode first collector 61 is an example of the collector disclosed herein. The negative electrode first collector 61 and the negative electrode second collector 62 may also be made of the same metal type as the negative electrode collector 24c, for example, a conductive metal such as copper, copper alloy, nickel, stainless steel, etc. The structure of the negative electrode first collector 61 and the negative electrode second collector 62 may also be the same as the positive electrode first collector 51 and the positive electrode second collector 52 of the positive electrode collector 50.

[0103] like Fig.11 As shown, the negative electrode first current collecting portion 61 has a negative electrode first region 61a and a negative electrode second region 61b. A negative electrode insulating component 80 is arranged between the sealing plate 14 and the negative electrode first region 61a. The negative electrode first region 61a is insulated from the sealing plate 14 by the negative electrode insulating component 80. The negative electrode first region 61a is electrically connected to the negative terminal 40 by riveting (the details will be described later). In the positive electrode first region 51a, a through hole 61h is formed in the up-down direction Z at a position corresponding to the terminal lead-out hole 19 of the sealing plate 14. As shown Figure 6As shown, the negative electrode second current collector 62 has a current collector plate connection portion 62a electrically connected to the negative electrode first current collector 61, an inclined portion 62b, and a tab joint portion 62c attached to the negative electrode tab group 25 and electrically connected to the plurality of negative electrode tabs 24t. The current collector plate connection portion 62a has a recessed portion 62d connected to the tab joint portion 62c. A through hole 62e penetrating in the short side direction X is provided in the recessed portion 62d.

[0104] like Fig.11 As shown, the positive electrode insulating member 70 is a member that insulates the sealing plate 14 from the positive electrode first current collecting portion 51. The positive electrode insulating member 70 is made of a resin material that has resistance to the electrolyte used and electrical insulation and is elastically deformable, and is preferably made of, for example, polyolefin resins such as polypropylene (PP), fluororesins such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polyphenylene sulfide (PPS), etc.

[0105] like Fig.11 As shown, the positive electrode insulating member 70 has a base portion 70a and a protruding portion 70b. Fig.11 As shown in FIG. 1 , in the longitudinal direction Y, the protrusion 70b is provided closer to the center side of the sealing plate 14 than the base 70a ( Fig.10 The base 70a and the protrusion 70b are integrally formed here. The positive electrode insulating member 70 is an integrally formed part formed by integrally forming the resin material as described above. As a result, compared with the case where the base 70a and the protrusion 70b are different components, the number of components used can be reduced, and low cost can be achieved. In addition, the positive electrode insulating member 70 can be prepared more simply. In addition, the same structure can be adopted for the negative electrode insulating member 80. The negative electrode insulating member 80 has a base 80a and a protrusion 80b arranged between the sealing plate 14 and the negative first collector 61 in the same way as the positive electrode insulating member 70.

[0106] As described above, the positive electrode first region 51a and the negative electrode first region 61a are electrically connected to the positive electrode terminal 30 and the negative electrode terminal 40 respectively by the riveting process and the joining (welding) of the subsequent process. In addition, the battery 100 of the present embodiment is characterized by the structure near the riveted portions 30b and 40b of the positive electrode terminal 30 and the negative electrode terminal 40. Hereinafter, the structure near the riveted portion 40b of the negative electrode terminal 40 will be described as an example, but the structure near the riveted portion 30b of the positive electrode terminal 30 is also the same. That is, in the following description, the part of the "negative electrode" can be appropriately replaced with the "positive electrode".

[0107] Figure 8 It is schematically indicated Figure 2 A partial enlarged cross-sectional view of the vicinity of the negative terminal 40. Figure 8As shown, the negative electrode current collecting portion 60 (specifically, the negative electrode first region 61a) of the present embodiment includes a through hole 61A for inserting the negative electrode terminal (specifically, the negative electrode terminal 40' before the caulking process). The through hole 61A includes a tapered portion 61d having an inner diameter extending in the insertion direction (i.e., Figure 8 The through hole 61A of the present embodiment also has a through hole first region 61c and a through hole second region 61e. The through hole first region 61c and the through hole second region 61e are formed to be approximately perpendicular (here, perpendicular) to the surface of the negative electrode first region 61a surrounding the through hole 61A. In addition, the negative electrode terminal 40 is riveted at the tapered portion 61d in a state arranged in the through hole 61A, and an outer peripheral smooth portion 40a having a step is formed on the outer peripheral edge of the riveted portion 40b. Moreover, a joint portion 61f is formed on the outer peripheral smooth portion 40a where the outer peripheral smooth portion 40a is joined to the edge of the through hole 61A, and there is a recessed portion 61g formed along the outer peripheral edge of the through hole 61A.

[0108] In addition, the outer peripheral smooth portion 40a of the present embodiment has a substantially annular shape (here, annular shape) when viewed from above. Figure 8 As shown, the ratio (q / p) of the outermost diameter q of the rivet portion 40b to the innermost diameter p of the through hole 61A is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be approximately 1.02 or more, preferably 1.05 or more. In addition, the upper limit of the above ratio (q / p) is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be approximately 1.5 or less, preferably 1.2 or less, and more preferably 1.15 or less. That is, the above ratio (q / p) can preferably be set within the range of 1.05 to 1.15.

[0109] Fig.9A , Fig. 9B It is schematically indicated Figure 2 A partial top view of the vicinity of the negative terminal 40. Fig. 9B As shown in FIG. 1 , the plan view of the joint portion 61f of the present embodiment is non-annular. That is, there is an area in the outer peripheral smooth portion 40a where the joint portion 61f is not formed. Here, the circumferential length s of the joint portion 61f (corresponding to Fig. 9B The ratio (s / r) of the length (the sum of the lengths s1 and s2 in the outermost portion) to the length r (not shown) of the outermost periphery of the outer peripheral smooth portion 40a is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be approximately 0.4 or more, preferably 0.5 or more, and more preferably 0.6 or more. In addition, the upper limit of the above ratio (s / r) is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be preferably 0.9 or less, and more preferably 0.8 or less.

[0110] like Fig. 9B As shown, the shape of the concave portion 61g in the present embodiment when viewed from above is non-annular. Fig. 9B The ratio (t / s) of the ratio (the sum of the lengths t1 and t2 in the joint 61f) to the length s in the circumferential direction of the joint 61f is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be approximately 0.5 or more, preferably 0.7 or more, and more preferably 0.8 or more. In addition, the upper limit of the above ratio (t / s) is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be approximately 1.5 or less, preferably 1.3 or less (for example, 1.2 or less), and more preferably 1 or less. That is, the above ratio (t / s) can preferably be set within the range of 0.7 to 1.3 or 0.8 to 1.2. And, as Fig.9A As shown in FIG. 1 , the center angle P of the recessed portion 61 g of the present embodiment is smaller than the center angle Q of the joining portion 61 f.

[0111] <Method of Manufacturing Battery 100>

[0112] The manufacturing method of the battery 100 is characterized in that the structure near the rivet parts 30b and 40b of the positive terminal 30 and the negative terminal 40 as described above is formed. The manufacturing process other than this can be the same as before. The battery 100 can be manufactured by preparing the battery case 10 (external body 12 and sealing plate 14), the electrode body group 20 (electrode bodies 20a, 20b, 20c), the electrolyte, the positive terminal 30, the negative terminal 40, the positive electrode collector 50 (positive electrode first collector 51 and positive electrode second collector 52), the negative electrode collector 60 (negative electrode first collector 61 and negative electrode second collector 62), and the positive electrode insulating member 70 and the negative electrode insulating member 80 as described above, and by a manufacturing method including, for example, a first installation step, a second installation step, an insertion step, and a sealing step. In addition, the manufacturing method of the battery 100 of the present embodiment is characterized in that in the above-mentioned first installation step, it includes as Fig.12 The process of steps S1 to S5 shown in the flowchart of FIG. 1 is a flowchart of FIG. 1 . In addition, the manufacturing method disclosed herein may further include other steps at any stage.

[0113] In the first installation process, make Fig.10 , Fig.11The first combined object shown. Specifically, first, the sealing component 90, the positive terminal 30, the positive first current collecting part 51, the positive insulating component 70, the negative terminal 40, the negative first current collecting part 61 and the negative insulating component 80 are installed on the sealing plate 14. Hereinafter, the installation of the negative terminal 40, the negative first current collecting part 61 and the negative insulating component 80 to the sealing plate 14 will be described in detail. In addition, in the manufacturing method of the battery 100 of the present embodiment, the installation of the positive terminal 30, the positive first current collecting part 51 and the positive insulating component 70 to the sealing plate 14 can also be carried out in the same way. That is, in the following description, the position of "negative electrode" can be appropriately replaced with "positive electrode". Hereinafter, appropriate reference will be made to Figure 8 , Figure 12 to Figure 14 Provide explanation.

[0114] First, in step S1 (preparation process), prepare Fig.13 The negative electrode first current collecting portion 61 shown in FIG. 6 is provided with a negative electrode first region 61a. The negative electrode first region 61a is provided with a through hole 61A, and the through hole 61A is provided with a tapered portion 61d having an inner diameter along the insertion direction (ie, Fig.13 The first negative electrode current collecting portion 61 of the present embodiment is also provided with a through hole first region 61c and a through hole second region 61e. Moreover, the through hole first region 61c and the through hole second region 61e are formed to be perpendicular to the surface of the negative electrode first region 61a surrounding the through hole 61A. That is, the through hole first region 61c and the through hole second region 61e are formed so that when the angle formed by the surface of the negative electrode first region 61a and the through hole first region 61c is set to θ1, and the angle formed by the surface of the negative electrode first region 61a and the through hole second region 61e is set to θ2, θ1 and θ2 become 90° (refer to Fig.13 By providing the through hole 61A with the through hole first region 61c, it is possible to appropriately reduce the gap that may be generated between the outer peripheral smooth portion 40a and the edge of the through hole 61A in step S4 (outer peripheral smooth portion forming step) described later (see Fig.14 (c) gap S). Thus, the outer peripheral smooth portion 40a and the edge of the through hole 61A can be joined with high precision, and by providing the through hole second region 62e, high-reliability riveting can be performed in step S3 (riveting step) described later, so that the battery 100 in which the reliability of the riveted portion 40b of the negative terminal 40 is more appropriately improved can be obtained.

[0115] In addition, the inclination of the tapered portion 61d (ie, Fig.13 θ3) is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be set to be in the range of approximately 50° to 70° (for example, approximately 55° to 65°).

[0116] Here, the thickness u in the downward direction D of the negative electrode first region 61a (see Fig.14 (a)) is about 1mm, the thickness v of the through hole first area 61c in the Z direction is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be set to approximately 0.1mm or more. In addition, in step S4 described later, from the perspective of effectively reducing the gap that may be generated between the outer peripheral smooth portion 40a and the edge of the through hole 61A, the above-mentioned thickness v can preferably be set to 0.2mm or more. The upper limit of the above-mentioned thickness v is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be set to approximately 0.4mm or less. The same is true for the through hole second area 61e. In addition, the length of the tapered portion 61d is not particularly limited as long as the effect of the technology disclosed herein is exerted, and can be set to approximately 0.3mm to 0.7mm. However, it is not limited to this.

[0117] Next, in step S2 (insertion process), the negative terminal (specifically, the negative terminal 40' before riveting) is inserted into the through hole 61A provided in the negative first current collecting portion 61. Specifically, the negative terminal 40' before riveting is inserted into the through hole 90h of the gasket 90, the terminal lead hole 19 of the sealing plate 14, the through hole 80h of the negative insulating member 80, and the through hole 61A of the negative first current collecting portion 61 from the upper side of the sealing plate 14 in order, so that it protrudes to the lower side of the sealing plate 14 (see Figure 8 , Fig.14 (a)).

[0118] Next, in step S3 (caulking process), the negative electrode terminal 40' inserted in step S2 is caulked at the tapered portion 61d of the through hole 61A to form a caulking portion 40b (see FIG. 1 ). Fig.14 (b)). Specifically, the components are clamped so that they are in a state where a compressive force is applied in the vertical direction Z, and the negative terminal 40 is struck by a riveting punch, so that the axial diameter of the negative terminal 40 bulges in a manner that abuts against the tapered portions 61e and 61d, and the components are riveted and fixed. Since the negative terminal 40 is fixed in a state of abutting against the second through-hole region 61e, the load in the vertical direction (i.e., the vertical direction Z) generated by the riveting punch can be used to appropriately prevent the negative first current collector 61 (specifically, the negative first region 61a) from deforming in the vertical direction. As a result, the reliability of riveting can be appropriately improved.

[0119] In step S4 (peripheral smooth portion forming step), the outer peripheral edge of the rivet portion 40b formed in step S3 is formed into a peripheral smooth portion 40a having a step (see Fig.14Here, as an example of a method for forming the outer peripheral smooth portion 40a, a ring punch can be cited. By performing the ring punch, the outer peripheral smooth portion 40a having a ring-shaped shape when viewed from above can be formed (see Fig.9A , Fig. 9B ). In addition, in this process, if Fig.14 As shown in (c), a gap S may be generated between the outer peripheral smooth portion 40a and the through hole 61A. Here, the size of the gap S in the longitudinal direction Y is not particularly limited as long as the effect of the technology disclosed herein is exerted, and is generally 0.5 mm or less, preferably 0.2 mm or less, and more preferably 0 mm. By reducing the size of the gap S, it is possible to perform the bonding in step S5 (bonding process) described later with high precision, which is preferred.

[0120] In addition, the negative electrode first region 61a of the present embodiment includes a recessed portion 61g formed along the outer peripheral edge of the through hole 61A (see Fig.13 ). The recessed portion 61g can be formed, for example, by laser etching the surface of the negative electrode first region 61a. According to the recessed portion 61g, the heat capacity near the joint 61f can be appropriately reduced (that is, the joint can be performed with less heat), and therefore, the thermal influence on the resin component around the joint 61f can be appropriately reduced.

[0121] In step S5 (joining step), the outer peripheral smooth portion 40a formed in step S4 is joined to the edge of the through hole 61A (see Fig.14 (d)). This joining can be performed by laser welding, for example. In addition, in the manufacturing method of the battery 100 of this embodiment, as Fig.9A , Fig. 9B As shown, a portion of the unjoined portion is provided (i.e., the joining portion 61f is formed into a non-annular shape when viewed from above). Thus, for example, when laser joining is performed, it is easy to confirm the orbital deviation of the laser. In addition, it is possible to appropriately prevent the joining start portion and the joining end portion from colliding. That is, the mechanical strength of the joining portion 61f can be appropriately improved. In addition, by setting the ratio (s / r) of the circumferential length s of the joining portion 61f to the entire circumferential length r of the outer smooth portion 40a within the range described in <Battery 100>, the above-mentioned effect can be more appropriately obtained.

[0122] Here, the size of the joint portion 61f in the vertical direction Z is not particularly limited as long as the effect of the technology disclosed herein is exerted. For example, when the thickness v of the through hole first region 61c in the vertical direction Z is about 0.2 mm, it can be preferably set to about 0.3 mm to 0.6 mm (for example, about 0.4 mm to 0.5 mm). However, it is not limited to this.

[0123] Through the above-described steps S1 to S5 , the gasket 90 , the sealing plate 14 , the negative electrode insulating member 80 , and the negative electrode first current collecting portion 61 are fixed integrally to the sealing plate 14 , and the terminal lead-out hole 19 is sealed.

[0124] The positive electrode terminal 30 , the positive electrode first electricity collecting portion 51 , and the positive electrode insulating member 70 can be fixed in the same manner as the negative electrode side described above. That is, they can be fixed through the processes of steps S1 to S5 described above.

[0125] Next, the positive electrode external conductive member 32 and the negative electrode external conductive member 42 are mounted on the outer surface of the sealing plate 14 via the external insulating member 92. In addition, the material of the external insulating member 92 may be the same as that of the positive electrode insulating member 70. In addition, the timing of mounting the positive electrode external conductive member 32 and the negative electrode external conductive member 42 may be after the insertion step (for example, after the injection hole 15 is sealed).

[0126] In the second installation step, the first combined object produced in the first installation step is used to produce Figure 5 That is, an electrode assembly 20 integrated with the sealing plate 14 is produced. Specifically, first, as Figure 6 As shown in FIG. 1 , three electrode bodies 20a with positive second current collecting portions 52 and negative second current collecting portions 62 are prepared, and are set as electrode bodies 20a, 20b, and 20c, and arranged in parallel in the short-side direction X. In this case, the electrode bodies 20a, 20b, and 20c can also be arranged with the positive second current collecting portion 52 on one side in the long-side direction Y ( Figure 5 The negative electrode second current collecting portion 62 is arranged on the other side of the longitudinal direction Y ( Figure 5 The two components are arranged in parallel in the manner of (on the right side of the figure).

[0127] Then, in Figure 4 As shown, in a state where a plurality of positive electrode tabs 22t are bent, the positive first collector 51 (in detail, the positive second region 51b) fixed to the sealing plate 14 and the positive second collector 52 (in detail, the collector plate connection portion 52a) of the electrode bodies 20a, 20b, and 20c are joined respectively. In addition, in a state where a plurality of negative electrode tabs 24t are bent, the negative first collector 61 fixed to the sealing plate 14 and the negative second collector 62 of the electrode bodies 20a, 20b, and 20c are joined respectively. As a joining method, for example, ultrasonic welding, resistance welding, laser welding, and the like can be used. In particular, it is preferred to use welding performed by irradiation with high-energy rays such as lasers. By such welding processing, a joining portion is formed in the recess 52d of the positive second collector 52 and the recess 62d of the negative second collector 62, respectively.

[0128] In the inserting step, the second combined product produced in the second mounting step is housed in the internal space of the outer body 12 . Fig.15 : is a schematic cross-sectional view for explaining the insertion process. Specifically, first, for example, an insulating resin sheet made of a resin material such as polyethylene (PE) is bent into a bag or box shape to prepare an electrode body holder 29. Next, the electrode body group 20 is housed in the electrode body holder 29. Then, the electrode body group 20 covered by the electrode body holder 29 is inserted into the outer casing 12. In the case where the weight of the electrode body group 20 is heavy, approximately 1 kg or more, for example, 1.5 kg or more, and further 2 to 3 kg, it is preferably as follows Fig.12 As shown, the electrode assembly 20 is inserted into the outer casing 12 in such a manner that the long side wall 12 b of the outer casing 12 intersects the direction of gravity (the outer casing 12 is placed on its side).

[0129] In the sealing process, the sealing plate 14 is joined to the edge of the opening 12h of the outer body 12 to seal the opening 12h. The sealing process can be performed simultaneously with the insertion process or after the insertion process. In the sealing process, the outer body 12 is preferably welded to the sealing plate 14. The welding of the outer body 12 and the sealing plate 14 can be performed, for example, by laser welding. Thereafter, the electrolyte is injected from the injection hole 15, and the injection hole 15 is blocked by the sealing member 16, thereby sealing the battery 100. As described above, the battery 100 can be manufactured.

[0130] The battery 100 can be used for various purposes, but can be preferably used for purposes that may be subjected to external forces such as vibration and impact during use. For example, it can be preferably used as a power source (driving power source) for a motor mounted on a mobile body (typically a vehicle such as a passenger car or a truck). The type of vehicle is not particularly limited, and examples thereof include plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), and electric vehicles (BEV). The battery 100 can also be preferably used as a battery pack formed by arranging a plurality of batteries 100 in a predetermined arrangement direction and applying a load from the arrangement direction using a restraining mechanism.

[0131] Several embodiments of the present invention have been described above, but the above embodiment is only an example. The present invention can also be implemented in various ways besides these. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in this field. The technology described in the claims includes technologies obtained by variously deforming and changing the above-mentioned exemplified embodiments. For example, part of the above-mentioned embodiment can be replaced with other deformation modes, and other deformation modes can be added to the above-mentioned embodiment. In addition, if its technical features are not described as essential technical features, they can also be appropriately deleted.

[0132] In the above embodiment, the positive terminal 30 and the negative terminal 40 are both provided with the structure near the caulking portion of the terminal disclosed herein, but the present invention is not limited thereto. For example, only one of the positive terminal and the negative terminal may be provided with the structure near the caulking portion of the terminal disclosed herein.

[0133] In the above embodiment, the structures of the through holes provided in the positive electrode first region 51a and the negative electrode first region 61a are set to be the same, but the present invention is not limited thereto. For example, a negative electrode collector having a negative electrode first region provided with through holes as in the above embodiment can be used as the negative electrode collector, and a negative electrode collector having a through hole as in the above embodiment can be used as the negative electrode collector. Fig.16 The positive electrode current collecting portion of the first positive electrode region 151a having the through hole 151A shown in FIG. Fig.16 As shown, the positive electrode first region 151a has a through hole 151A, and the through hole 151A has a through hole second region 151e and a tapered portion 151d. The positive electrode terminal 130 is riveted at the tapered portion 151d, and an outer peripheral smooth portion 130a is formed at the outer peripheral edge of the riveted portion 130b. In addition, a joint portion 151f is formed by joining the outer peripheral smooth portion 130a to the edge of the through hole 151A.

[0134] In the above embodiment, the negative electrode first region 61a is described as including the through hole first region 61c, the tapered portion 61d, and the through hole second region 61e, but the present invention is not limited thereto. Fig.17A As shown in FIG. 1 , the negative electrode first region 161a may include only the tapered portion 161d. Fig. 17B As shown in FIG. 2 , the negative electrode first region 261a may include the through hole first region 261c, the tapered portion 261d, and other regions. Fig. 17C As shown in FIG. 1 , the negative electrode first region 361a may include a through hole first region 361c, a tapered portion 361d, a through hole second region 361e, and other regions. Fig.17D As shown, the negative electrode first region 461a may be provided with only the through hole second region 461e and the tapered portion 461d. Alternatively, the negative electrode first region may be provided with only the through hole first region and the tapered portion. The same is true for the positive electrode side. In addition, various other methods may be used in addition to the above.

[0135] In the above embodiment, the thicknesses of the through hole first region 61c and the through hole second region 61e in the Z direction are set to be the same, but the present invention is not limited thereto. Their thicknesses may be different. The same applies to the positive electrode side.

[0136] In the above embodiment, the through hole first region 61c, the tapered portion 61d, and the through hole second region 61e are connected at points, but the present invention is not limited thereto. For example, they may be connected at fillets instead of points. The same is true for the positive electrode side.

[0137] In the above embodiment, the outer peripheral smooth portion 40a and the surface of the negative electrode first region 61a are formed to exist in the same plane, but the invention is not limited to this. For example, the outer peripheral smooth portion 40a and the surface of the negative electrode first region 61a may be formed to exist in different planes as long as the effect of the technology disclosed herein is exerted. The same is true for the positive electrode side.

[0138] In the above embodiment, the shape of the outer peripheral smooth portion 40a when viewed from above is set to be annular, but it is not limited to this. For example, the outer peripheral smooth portion can be set to a state where a part of it is missing (that is, it can be roughly annular or non-annular). In addition, in the above embodiment, the shape of the joint 61f and the recessed portion 61g when viewed from above is set to be non-annular, but it can also be roughly annular. Moreover, in the above embodiment, if Fig.9A As shown, the joint portion 61f and the recessed portion 61g are formed symmetrically with respect to the center line T of the outermost periphery of the outer peripheral smooth portion 40a, but the present invention is not limited thereto and the joint portion and the recessed portion may be formed asymmetrically with respect to the center line T. The same is true for the positive electrode side.

[0139] In the above-described embodiment, the recessed portion 61g is formed along the through hole 61A, but the present invention is not limited thereto, and a configuration in which no recessed portion is formed may also be adopted. The same applies to the positive electrode side.

[0140] In the above embodiment, the "conductive member" is described as a collector (i.e., the positive electrode collector 51, the negative electrode collector 61), but it is not limited to this. The technology disclosed herein can also be preferably applied to the case where the "conductive member" is an external conductive member (i.e., the positive electrode external conductive member 32, the negative electrode external conductive member 42).

Claims

1. A battery, comprising: an electrode body, which includes a positive electrode and a negative electrode; A battery case including an outer casing having an opening for housing the electrode assembly and a sealing plate for sealing the opening; a terminal electrically connected to the positive electrode or the negative electrode and passing through a terminal lead-out hole provided in the sealing plate; and a conductive member connected to the terminal, in, The conductive member includes a through hole through which the terminal is inserted. The through hole has a tapered portion having an inclination such that the inner diameter gradually increases along the insertion direction of the terminal. The through hole includes a through hole first region at a position farther from the sealing plate than the tapered portion, and the through hole first region is formed substantially perpendicular to a surface of the conductive member constituting a periphery of the through hole. Here, the terminal is caulked at the tapered portion while being arranged in the through hole, an outer peripheral smooth portion having a step is formed at the outer peripheral edge of the caulked portion, and a joint portion exists where the outer peripheral smooth portion is joined to an edge of the through hole.

2. The battery according to claim 1, wherein The outer peripheral smooth portion has a substantially annular shape in plan view.

3. The battery according to claim 1, wherein The thickness of the through hole first region in the insertion direction of the terminal is 0.2 mm or more.

4. The battery according to any one of claims 1 to 3, wherein The through hole includes a through hole second region at a position closer to the sealing plate than the tapered portion, and the through hole second region is formed substantially perpendicular to a surface of the conductive member constituting a periphery of the through hole.

5. The battery according to any one of claims 1 to 3, wherein A ratio of an outermost diameter of the rivet portion to an innermost diameter of the through hole is in a range of 1.05 to 1.

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6. The battery according to any one of claims 1 to 3, wherein The outer peripheral smooth portion includes a region where the bonding portion is not formed.

7. The battery according to any one of claims 1 to 3, wherein The outer peripheral smooth portion is roughly annular in plan view. The joining portion has a non-annular shape when viewed from above.

8. The battery according to any one of claims 1 to 3, wherein The conductive member has a recessed portion formed along an outer peripheral edge of the through hole.

9. A method for manufacturing a battery, the battery comprising: an electrode body, which includes a positive electrode and a negative electrode; A battery case including an outer casing having an opening for housing the electrode assembly and a sealing plate for sealing the opening; a terminal electrically connected to the positive electrode or the negative electrode and inserted into a terminal lead-out hole provided in the sealing plate; and a conductive member having a through hole through which the terminal is inserted, in, The following steps are included: A preparation step of preparing the conductive member having a through hole, the through hole having a tapered portion having an inclination such that an inner diameter gradually increases along a direction in which the terminal is inserted, the through hole having a through hole first region at a position farther from the sealing plate than the tapered portion, the through hole first region being formed substantially perpendicular to a surface of the conductive member constituting a periphery of the through hole; an inserting step of inserting the terminal into the through hole; a riveting step of riveting the terminal at the tapered portion of the through hole, thereby forming a riveted portion on the terminal; an outer peripheral smooth portion forming step of forming a step at the outer peripheral edge of the riveted portion to form an outer peripheral smooth portion; as well as The joining step forms a joining portion between the outer peripheral smooth portion and the edge of the through hole.

10. The method for manufacturing a battery according to claim 9, wherein: In the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed so as to have a substantially annular shape in plan view.

11. The method for manufacturing a battery according to claim 9, wherein: The thickness of the through hole first region in the insertion direction of the terminal is 0.2 mm or more.

12. The method for producing a battery according to any one of claims 9 to 11, wherein: The through hole includes a through hole second region at a position closer to the sealing plate than the tapered portion, and the through hole second region is formed substantially perpendicular to a surface of the conductive member constituting a periphery of the through hole.

13. The method for producing a battery according to any one of claims 9 to 11, wherein: In the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed so that a ratio of an outermost diameter of the caulking portion to an innermost diameter of the through hole is within a range of 1.05 to 1.

15.

14. The method for producing a battery according to any one of claims 9 to 11, wherein: In the bonding step, a region where the bonding portion is not formed is provided in the outer peripheral smooth portion.

15. The method for producing a battery according to any one of claims 9 to 11, wherein: In the outer peripheral smooth portion forming step, the outer peripheral smooth portion is formed to have a substantially annular shape in plan view, and in the joining step, the joining portion is formed to have a non-annular shape in plan view.

16. The method for producing a battery according to any one of claims 9 to 11, wherein: The conductive member has a recessed portion formed along an outer peripheral edge of the through hole.

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